If you want to go for a more believable setting, perhaps consider one where Modernism was soon overtaken by a more gothic style of modernism. Perhaps some Texan guy gets elected President of the United States and inspires people into doing things "in a BIG way" and "putting DOO DADS on it for SYLE".

You could put Lyndon Johnson in the White House any time after about 1952, or invent some other Texan guy for the purpose.